Pressure casting apparatus



July 17, 1951 w. R. LING PRESSURE CASTING APPARATUS 2 Sheets-Sheet lFiled Sept. 27, 1948 July 17, 1951 w. R. LING PRESSURE CASTING APPARATUS2 Sheets-Sheet 2 Filed Sept. 27, 1948 AWAY/W/ /3- INVENTOR. wan-e2 R.Lam; W

Patented July 17, 1951 UNITED STATES PATENT O FFICE PRESSURE CASTINGAPPARATUS Walter R. Ling, Birmingham, Ala. Application September 27,1948, Serial No. 51,418

6 Claims.

. 1 My present invention relatesv to apparatus for applying pressure tocastings immediately after the same are poured, whereby the necessaryfeeding of'the'mo1ten meta1 to the solidifying'casting is facilitated,resultingin a finished casting free of faults, and one in which thegrain structure of the metal is more dense than the castings pouredunder atmospheric pressure.

In the art to which my invention relates, it has heretofore beenproposed to pour metal into a mold and subsequently to apply pressure tothe moltenmetal at the pouring gate. However, the apparatus heretoforeproposed for accomplishing this has not been sufiiciently satisfactoryfor this method to come into general foundry practice. For instance, ithas heretofore been considered necessary to use very high pressures,thus necessitating the use of'heavy, strong apparatus, generallycomprising steel or plaster molds. Further, insofar as I am aware, ithas not been proposed heretofore to pour the metal through a pouringgate, then seal the gate in the manner taught herein, and then to putthe metal in the riser under ,/pressure while in association with meansto maintain the metal in molten condition, thereby furnishing a supplyof molten metal for feeding the casting during solidification. Moreparticularly, none of the prior art apparatus has embodied means forplacing on top of the metal in the riser a material for aiding inmaintaining the metal in molten condition to permit the same to feedinto the main body of the casting as the same solidifies, together withsuitable means to seal the riser at the point of contact with the sandof the mold.

In seeking to overcome the deficiencies of prior apparatus, I have foundthat for large and medium castings made in molds of sand or the like, itis necessary to provide means for holding the riser securely to the moldso that the riser will not separate therefrom when-the metal ispouredand pressure is applied. On the other hand, the risers must be sosecured as not to endanger the mold by c aving in the same, and thehold-down mechanism must be capable of being quickly-applied to'andremoved from the flask, and must be simple and economical ofmanufacture.

Accordingly, an. object of my invention is to provide apparatus of thecharacter designated in which the riser for the mold is in the form of ahollow refractory liner and a metallic holder or shell removablysurrounding the same, together with quick connecting clamps for holdingthe shell and hence the liner in position on the mold.

A further object is to provide a removable cap for sealing the upperopen end of the liner which is connected to the shell by bolts, therebypermitting the liner to be pressed into contact with the sand of themold with a positive yet controllable degree of pressure, whereby thedanger of breaking the sand and spoiling the mold is eliminated.

My invention further contemplates the provision of apparatus of thecharacter designated which in slightly modified forms is especiallyadapted for pouring large, medium, and small castings, and which in allmodifications may readily be attached to and detached from exist.- ing,standard fiasks carrying molds of sand or the like.

A still further object is to provide apparatus embodying the aboveenumerated features in which thepourin gate is sealed after the metal ispoured by placing thereover a weight, whereby when air under pressure isadmitted to the riser, the pressure is eifective'to cause theconfinedjleodyofmolten metal to flow into all parts of the mold,eliminating faults in the casting, and improving the grain structure ofthe metal.

Apparatus illustratingthe features of my invention is shown in theaccompanying drawing forming a :part of this application in which:

Fig. 1 is a plan View of one form of my improved ;apparatus in place ona flask;

Fig. 2 is a sideelevational View partly broken away and .in section;

Fig. 3 isa fragmental end view of the apparatus shown in Fig. '1;

Fig. 4 is a .detail sectional view drawn to an enlarged scale "and takengenerally along line Iv-Iv of Fi 1;

Fig. 5 is av View similar to Fig. 4 and showing my improved riserassociated with a pipe eliminating wafer of refractory material;

Fig. ,6 is a plan View of the wafer shown in Fig. 5;

Fig. 7 is a'plan viewof a modified form of my invention;

Fig.,,8 is an end elevational view ofthe apparatus shown in Fig. 7;

Fig. 91s a detail sectional View "drawn to an enlarged scale and takenalong line IXIX of Fi 7 Fig.10 is an end elevational view, partly brokenaway and in section'and illustrating yet another modified form of myinvention; and,

Fig. 1 1 .is 'adetail sectional View showing the weight applied to theriser of the device shown in Fig. 10.

. provide an opening parallel bars are adapted to straddle the bolts 24.The cap is Referring now to the drawings for a better understanding ofmy invention and more particularly to Figs. 1 to 4 inclusive, I show myinvention in association with a well known form of flask havingsuperposed cope and drag sections 13 and H. The cope and drag sectionscomprise rectangular frames i la into which is packed a bed of sand I2.As understood, the sand I2 is packed about a pattern which is drawnbefore the cope and drag sections aremate'd, thus to l3 for receivingthe molten metal and of a shape to conform to the casting desired. Asprue hole l4 connects the opening I'3 with a pouring gate 16 comprisinga refractory member i'i having an opening I8 therein in communicationwith a vertical end l9 of the sprue hole I l. The pouring gate may beplaced on any convenient part of the flask and connected to the opening13 by sprue holes of various sizes and lengths, the size, length andconfiguration of which will be readily apparent to those skilled in theart.

As likewise is well understood, the space I3 into which the molten metalis to be poured is vented at one or more places by a second opening 2!.My improved riser, presently to be described, is disposed to be placedand held over the opening 2 l, whereby when metal is poured into thepouring gate it the same rises thereinto.

Referring more particularly to Fig. 4, my irn-v proved riser comprises afrusto-pyramidal shell 22, made of welded plates or the like, and withits base disposed downwardly. Welded to opposite sides of the shell 22are angles 23 of a length to span the flask. Welded to the sides of theshell 22 adjacent the top are bolts 24. Slidably fitting within theshell 22 is a frustopyramidal refractory lining 23 having a throughopening 21 therein. The liner 26 is disposed to fit with slightclearance in the shell 22 when the same is in pouring position on themold for a reason later to appear.

The angles 23 and shell 22 carried thereby are placed on top of theflask, and preferablyrest on spacer blocks 28 resting on the frame Ha ofthe flask, thereby to hold the bottom of the shell and the angles out ofcontact with the top of the sand 12. The angles are secured to the flaskby means of L-shaped clamps 29 having a foot portion 3| disposed toengage beneath the flask, and a sliding member 32 adapted to'flt over aplate 33 spanning the top of the angles. The leg of the clamp may beprovided with a number of openings 34 into which are driven tapered pins36, passing through the sliding members 32, thereby to hold the anglesand shell 22 clamped positively to the flask. The upper end of' theshell 22 is provided with a cap 31 in the form of a plate having a bead33 on its underside. Welded on top of the cap 31 are spaced 39, theoverhanging ends of which held in place by the provision of washers 40and nuts M.

The plate 31 has an opening 42 therein in which'is tapped or welded aconduit 43. The conduit 43 carries one portion 44 of a quick connectingcoupling. The other mating end lfi of the quick connecting coupling iscarried on the end of a conduit 41, leading through amanually operatedvalve 48 and a pressure regulating valve 49 to a source of air underpressure, not shown. From the description so far given, the method ofassembling my improved apparatus for use may now be explained. With thecope and dra n'um oxide and the like.

sections of the flask in superposed relation, and after the sprue holesand openings 21 are provided, the pouring gate i6 is put in place. Aring of suitable sealing material 5| is placed around the opening 2| andover this ring is placed a sheet of paper or other combustible material52. On top of the paper 52 I place the lower end of the refractorylining 26, and in the opening 22 thereof I place a smallamount 530i anyof the well known pipeeliminating materials, such as powdered coke,lime, alumi I next place the shell 22 over the liner 2E and secure theangles 23 to the flask with the spacers 28 in place. The tapered pins 36are now driven into a selected one dentally clamping the cope and dragsections to-' gether. The assembly is completed by placing a rubbergasket 54 on top of the liner 26, put- .ting the cap in place andrunning in on the bolts 4L, The molten metal is now poured through thepouring gate and flllsthe casting space 13. The metal rises by gravityup into the riser to the level that the same occupies in the pouringgate, burning through the paper '52 andfloatin the compound 53 on itssurface. It will be noted that the paper 52 supports the material 53above the casting space l3 untilfthe molten metal burns through thepaper, thus preventing the material 53 from falling .into th e ,castingspace before the metal has risen to a level above the casting space. Thepouring is stopped after the metal in the pouring gate and riser reachapproximately the line 56. I now con flne the metal against flowing outof the pouring gate by chilling the surface of the metal therein withwater,or by placing a small amount of sand or the'like on top of themetal in the pouring gate and placin thereover a weight l5. Immediatelythereafter the quick connecting coupling is connected and air isadmitted'to the riser by opening the valve 48. The molten metal is thusput under pressure, the same being confined by the chilled surface inthe gate or the weight 15. While thepressure applied to the riser mayvary somewhat, I have found that about 3 to 5 pounds per square inchgauge'is sufficient for most castings.

Referring now particularly to Figs. 5 and 6, I show my improvedapparatus assembled with a wafer 52 of refractory material interposedbetween the top of the mold and the refractory liner 26. As isunderstood by those skilled in the art, the wafer 5'! has an opening 58therein which is of less area than the opening 2! and theopening 21 inthe lining. It'has been found that such an arrangement further aids inmaintaining the metal molten for a longer period of time'.

In' order to effectively seal the apparatus just described I may em myrings 59 and BI of the sealing" material at top and bottom of the waferand I may interpose the sheet of paper or the The shell 22 is providedwith three or more eyes 54, welded. equieangularly 'thereabout. Disposedto flt in each of the'eyes 64, is the hook end 66 of a rod- 61,thread'e'don its outer end as at B8.

A similar "rod 59 hasa'hook end H secured in a staple or the like.lztin'therframe Ila of the flask and the tworods. are. connected by. aturn buckle 73. I

The angles 23 are omitted from the shell 22 in this embodimentandthepressureof the liner 26 against the sand is regulated by the' turnbuckles- 13 5 .A, cap 1.6,..similar toicap 37', carries thequick.connecto.r..coupling:,member 4.4, and thedeviceuissassemblediompouring substantially as: above described.-. .The.turn, buckles: l3. and threadedsrods.68.and 69rprovide;simplerandueasilyoperated meansior. securing. the angles. and s-helLtothefiask,..and.the..hooks H are; disengageableafrom, the .staples-.-.12.Likewise, this modification; has. the further: advantage; of providing;clearance, for... gagger rods and-(the. like projecting above thelevel-of the mold.

The form of'my invention Shown in Figs. 7, 8 and '9' 'is especiallyadapted for making castings of medium size. It wil-l' be understood thatthe pouring gate is sealed by means of chilling or by the weight l5after the metal is poured and that pressure is admitted to the riser bymeans of the valve 48.

In Figs. 10 and 11 I show a form of my invention especially adapted forpouring the smaller type of casting and in which the entire shell andrefractory liner for the same is supported directly from the sand bed l2of the mold. As shown, the liner 26 is placed in a shell 15, similar totheshell 22. The liner is sealed at the bottom by a ring 5| of thesealing material similar to the rings 59 and 6|. I seal the top of theliner 26 by means of a Weight 78 resting on a rubber gasket 54. In thismodification, the shell is of a size to fit closely about the linerwhereby the lower end of the shell is held out of contact with mold.

The weight 18 has an opening 8| therein forming a compression chambercommunicating with the central opening 21 of the liner 26. The airconduit 82 is threaded into the weight at the top to communicate withthe chamber 8|, and carries the portion 44 of the quick connectorcoupling. The weight is employed to seal the pouring gate in the manneralready explained, and the weight 13 may be provided with a bead 83 tocooperate with the gasket 54 in sealing the top of the refractorylining.

From the foregoing it will be seen that I have provided an improvedapparatus for pouring molten metal into a mold in which the metal issubjected to pressure while in a molten condition. In actual operation Ihave found that my apparatus results in castings which are free offaults and in which the metal is considerably improved as to strengthand quality. In the modification shown in Figs. 1 to 6 inclusive whereinthe opening 21 in the refractory lining 26 may of necessity be ratherlarge, thereby to provide a sufiicient reservoir for feeding thecasting, I eliminate the possibility of spoiling the mold by supportingthe shell 22 from the mold frame and secure a controllable sealingpressure through the medium of the nuts 4| on the bolts 24. In actualoperation I have found that my apparatus is satisfactory in every Wayand that the same is both simple and economical of manufacture.

While I have shown my invention in several forms, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various other changes and modifications, without departing from thespirit thereof, and I de- Ill) 6. sire. therefore; that QIflYoSuch;limitations: shall be placedethereunonasvare specifically'set forth inthe;anpendedtclaimsz.,.;

whatisliclahnrist: L.) e

1. Ini: pnaratus on-makingypressure castings in sat-divided moldhaving-pouring; and vent" openingsi wherein when. 'inspou-rin relationtheparts of the:"m01d'. are superposed-1together; with arefractory:riser .having -a through opening. therein, said riser; beingrdisposedgtoarest n' the mold with. its. openings in communication. with the Ventp g h reQf-;;.the 'combin'atiomof aimetallicvshjell slidably/. fitting:about the riser and of less height ythan the riser; smembers carried by;the-:s-hellv and: extending across; the; .mold, clamps forsimultaneously; securing-lsaidzmembers 1150 r th molds and Clamping; theparts: of the moldptogether; a: removable cap. for closing the top of;the'rriserropening fastening .means .on; the upper .endri'ofjzthe, shellor; drawingxthe. cap, onto t e 2 12212611lendwofagthe riser: and:simultaneously movingrtlre samejz'downwardly to seal the lower end ofthe riser against the surface of the mold, means to seal the pouringopening after metal is poured therethrough, and means to admit air underpressure through the cap onto the surface of the metal in the riser.

2. In apparatus for making pressure castings in a mold having pouringand vent openings and a refractory member having an opening thereinmounted on the mold with said opening in communication with the ventopening, the combination of a sheet of combustible material interposedbetween the lower end of the refractory member and the mold, a quantityof heat retaining material within the refractory member and on top ofthe sheet of material, a cap for sealing the upper end of the opening inthe refractory member, means to seal the pouring openin after the metalis poured, the metal being disposed to burn through said sheet and riseinto the refractory member floating said heat retaining material, andmeans to admit air under pressure through the cap into the surface ofthe metal in said refractory member.

3. In apparatus for making pressure castings in a mold having a pouringgate and a vent opening and a refractory member having an openin thereinmounted on the mold, the combination of a metallic shell slidablyfitting about the refractory member, means to secure the shell to themold with the lower end of the shell out of contact therewith and withthe opening of the refractory member in communication with the ventopenin of the mold, a cap for the upper end of the opening of therefractory member, bolts carried by the shell, and passing slidablyupwardly through said cap, nuts for the bolts for drawing the cap intosealing relation with the upper end of the refractory member, means toseal the pouring gate after the metal is poured, and means to admit airunder pressure through the cap into the surface of the metal in saidrefractory member.

4. In apparatus for making castings in a mold having a riser opening anda pouring gate, a riser and support therefor comprising an outermetallic shell and a centrally open refractory liner slidably fittingwithin said outer shell and disposed to rest on the mold with theopening thereof in communication with the riser openin of the mold andwith its upper end projecting through the upper end of the outer shell,members rigidly secured to the outer shell ex tending across and securedto the edges of the mold and holding the lower end of the shell out ofcontact with the mold, upwardly extendin bolts on the upper end of theouter shell, a removable cap on'the projecting upper end of the linerhaving holes in the edge thereof through which said bolts loosely pass,nuts on said bolts disposed to draw the cap into sealing contact withthe upper end of the liner, means to seal the pouring gate after themetal is poured and means to admit air under pressure through the capinto the refractory member.

5. Apparatus as defined in claim 4 in which the central openin of theliner is smaller in transverse sectional area at the lower end of theliner than at the upper end thereof.

6. Apparatus as defined in claim 4 in which the liner and outer shellare frusto-pyramidal, and in which the central opening of the liner islarger in transverse sectional area at the upper end of the liner thanat the lower end thereof.

WALTER R. LING.

REFERENCES oI'rEfi The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Great Britain Oct. 22, 1879

